With regard to such an electric rotating machine as described above, an electric rotating machine disclosed in Patent Document 1, described below, is known. Here, the sides, in the axial direction, that depart from the rotor are defined as the axial-direction departing sides. In the technology disclosed in Patent Document 1, on the rotation axle, respective small-diameter portions whose diameters are smaller than those of fan fixing portions are provided at the axial-direction departing side than the fan fixing portions to which axial-flow fans are fixed; the respective radial-direction outer sides of the small-diameter portions are covered with fan guides.